Permethrin is a predominant pyrethroid widely used in agriculture and publi
c health. A competitive enzyme-linked immunosorbent assay (ELISA) for the d
etection of permethrin was developed. Two haptens, the trans- and cis-isome
rs of 3-(4-aminophenoxy)benzyl-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopro
panecarboxylate, were synthesized and conjugated with thyroglobulin as immu
nogens. Four antisera were generated and screened against six different coa
ting antigens. The resulting ELISA has an I-50 value of 2.50 mu g/L and rel
atively low cross-reactivities with other major pyrethroids, such as esfenv
alerate, cypermethrin, deltamethrin, and cyfluthrin. Methanol was found to
be the best solvent for this ELISA, with optimal sensitivity observed at a
concentration of 40% (v/v). The assay parameters are unchanged at pH values
between 5.0 and 8.0, whereas higher ionic strengths (>0.2 M PBS) strongly
suppress the absorbances. River water samples fortified with permethrin wer
e analyzed according to this method and validated by GC-MS. Good recoveries
and correlation with spike levels were observed, suggesting this immunoass
ay is valuable for environmental monitoring and toxicological studies at pa
rts per trillion levels of permethrin.